1.1 What is anaerobic digestion?

Anaerobic digestion (AD) is a biochemical process that decomposes complex organic matter without (gaseous) oxygen using various anaerobic microorganisms. The process is also known as anaerobic fermentation, bio-methanation, or biogas treatment, and it produces biogas.

The process occurs naturally in the stomachs of ruminant animals, marshes, organic sediments from lakes and rivers, swamps, and other oxygen-free environments.

The process is used in a designed environment like biogas plants, septic tanks, and other anaerobic treatment options.